My Team usually looks like this:
Espeon
Dragonite (or salamence)
Absol
Manectric
Blaziken
Walerin
Blaziken helps with it's fighting co-type, salamence is fatal with the Intimidate/ dragon flying features and high stats, but dragonite is a personal favourite
Absol is also fatal if you use it right
Manectric can help, but you can use flygon or swellow too
anyway, keep this in mind
1- have a fighting pokemon in your team, they help alot
2- dragon are invisible in these generations, and if you have a Kingdra, you're be a hero coz it's only weakness is dragon type itself
3- fire and ice moves are so helpful, make sure to be equipped with them
4- Espeon can hurt badly, find a timid one and teach it shadow ball, psychic, calm mind and toxic, you'll be rewarded big time :)